I always think experiments like this is quite charming. It seems the guys at ETA thinks the same since the movement (2824-2) can surface with a big array of different configurations.
The automatic bridge in the 2783 is quite similar to an 2824-2 but not quite exact.
Though the dimensions might vary as in this case the outer dimensions, many of the parts still are interchangeable.
Here is an 2824-2 with an classic incablock balance bridge.

Ok I have to confess I began to read up on clocks and follow the threads here and enjoying them very much. I have almost gone over to the dark side
As usual when my interest have been triggered I will come with a bunch of strange questions.
1. Is there a clock movement type one should avoid as a beginner?. (cuckoo clocks are already out of the question for now!)
2. Which tools are essential to acquire, I guess most of my watch repair tools are a bit tiny for clocks?.
3. Is there any book clock makers considers as essential reading?.

Okay done reading and got a practice movement the other day. It's obviously a German Badishe of some kind but seemed to be easy enough for a start.
Here are some pictures of it but unfortunately I got so excited tinkering with it I forgot to take more pictures.

This would be extremely intresting I think not just for me but to countless other members on this forum that has been thinking of making or restoring dials.
So if you are up to it please make a small tutorial of this process.

Just by judging from this one photo it´s hard to make any estimations
So just as a start and considering it stopped by the balance bridge I would suggest you take off the Winding mechanism and look at the backside of the swing weight. if it is getting caught in something like the screw holding the balance bridge you should see some scratches on the backside of it.
In general you should do something about the screwheads along the path the weight travels since they seem to have quite a loot metal shavings sticking up, just give them a quick polish so they are nice and flat othervice you might end up with small metal shavings inside the mechanism.

Got lot of it and orderd the rest. I even got me a Badishe Movement in a horrible state of course while I was on it.
The Donald De Carle book I bought for a starter was named "Practical Clock Repairing" hope it was what you ment, I have packed it down in my luggage since it will be my evening amusement while I am on a bussiness trip this week.
Thanks for the advice.

Just some thoughts about the amplitude in the 28XX series.
To get maximal amplitude before regulating these beauties I use to let it take some time. If one follow the oiling scheme in the tech notes one should get a quite good amplitude.
The important step in the process is to let the movement run for at least a day or two before starting regulating the movement with a time graph. If you measure the amplitude just after servicing you will get a lower reading which is natural. To get maximum lubrication one have to let it get worked in and spread out on the surfaces.
To gain maximum amplitude on these ETA Movements or any one else I guess it is of most importance to learn how to oil/grease the jewels on the pallet fork with for example Moeibus 9415. In my experience this boosts the amplitude significant.
To get an amplitude of 300 one have to do the complete service including main spring change.
When I get the amplitude to 280 or higher i begin the regulating work.
Hope these observations can help you in some way.

Just finished a quite extensive session with these beauties to try replicate the fault you mention.
Nothing except total loss off power by heavy dirt in the drive train would make it stop the balance from oscillating by it self. I used a small drop of maple syrup to simulate an old oil. So we can rule the drive train out.
I didn't find any worn balance pivots in my goodie bag just some broken ones so that test is unfortunately excluded and you just have to check the end shake and side shake with a couple of tweezers.
Here comes a small checklist from the tests.
Too much oil on the escape teeth made it hard to get oscillate by it self.
Dirt on either entry or exit pallet made it hard to get oscillate by it self.
Too much oil in the escape wheel pivot made it hard to get oscillate by it self.
Oil accidentally applied on the pallet fork pivots made it hard to get oscillate by it self and later went into a halt.
Dry balance jewels made it occasionally hard to get oscillate by it self.
Broken pivot jewel in the balance made it hard to get oscillate by it self and go to a stop when turned around.
Dirt in the impulse pin made it hard to get oscillate by it self.
Broken pivot on balance staff lower part made it hard to get oscillate by it self, stopped when turned around.
A slight bend upwards on the pallet fork made it hard to get oscillate by it self.
Beat error lever accidentally moved out of position made it hard to get oscillate by it self.
A magnetized hairspring made it hard to get oscillate by it self.
To speed up this small investigation I had to add one more movement into the process it got to be the lucky one with magnetized hairspring.
So if you have cleaned the movement correctly and checked the items in the list I can't se any other reasons for the balance not to swing like on the one in the attached video.
6942.mp4

That doesn't sound very good, this movement has the second stop function, if you pull out the winding stem it ticks until the second hand is in zero position. This is a quite handy function while setting the watch but might introduce some weird faults.
But as a fault finding exercise we could start here.
Begin with releasing all power from the mainspring, you do this by lifting the click.
Pull the stem out and remove the balance bridge.
Remove the pallet cock and pallet fork.
Put the stem back in and put it in setting position. Now turn one or two times on the winding stem. Nothing should happen at this stage.
Push the stem into winding position, now you should have a release of power, the train wheels and escape wheel should rotate free.
Look at the escape wheel it should run free slightly longer than the train wheels. If not there is to much oil. Clean it off with Rodico.
When faultfinding you could clean out the oil from the escape since it just going to run for a short while. The oil already stuck on the pivot pin should be enough.
If everything runs great here we have a problem either in the pallet fork area or the balance area.
Sometimes the juvels are slightly different you could always try to switch them after you checked the drive train.
I will setup a test station trying to replicate the error but that might take a while. I got three volunteers.

Andy that was an impressive presentation got to admire your engagement , in my trade we wright a huge deal of research reports but not in this speed .
A while ago I watched this video, shows some of the steps needed for a perfect professional result.
Those logo negatives they use for printing are made in the same way as a printed circuit bord, photo negative. Maybe time to pick out the old kit?

The Longines 6942 is quite straight forward to service but since it is equipped with the KIF-ultraflex shock absorber some might decide to just clean the whole balance in one-dip, oil it through the
jewel hole and leave it with that.
So here is a small walk through of how one might do to dismantle parts of the escapement to get this sorted out in a different way.

Somehow statements like that comes back to bite you in the ass.
Even though this contraption is on the beat error arm it can be used to regulate the rate, python port regulator, hence the + and - .
It has a smal brass disk attached to the center of the small setting screw, it moves back and forth. Due to the friction between the brass disk and the regulator arm it moves it in micro steps.
For some reason one always seen them but never given em a closer thought.
Here is a pic of a spare I had. Notice the easy studless hairspring attachment.

Guess they just symbolize the direction to go when adjusting the beat error. It isn't like on the regulator where you make the spring length shorter or longer and by that increase or decrease the oscillation frequency. Should have been R & L since you center the impulse pin in relation to the pallet fork with it,

Flip the movement, make sure no power is in the mainspring by lifting the click spring. Push the winding stem back in into the
winding position. Gently wind an see if the train moves free. Make sure you clean the pallet fork jewel holes with a peg wood.